Recent progress in layered rare-earth hydroxide (LRH) and its application in luminescence

Abstract

Abstract:This review article compiles the recent achievements made in layered rare-earth (RE) hydroxide (LRH), including controlled crystallization, structural and morphological features, anion exchange, nanosheet exfoliation, and application in the field of luminescence for both the Ln 2 (OH) 5 (A x ) 1/x ·nH 2 O (251-LRH) and Ln 2 (OH) 4 (A x ) 2/x ·nH 2 O (241-LRH) phases. The luminescent properties of the LRHs themselves, the oxide, oxysulfate, and oxysulfide phosphors derived from the LRHs via controlled calcination, and the highly oriented transparent phosphor films of enhanced luminescence and/or novel emission features are summarized.

Luminescent sensing film based on sulfosalicylic acid modified Tb(III)-doped yttrium hydroxide nanosheets

“…Lanthanides nanomaterials and complexes play an important role in inorganic chemistry and materials science, because of their unique spectral characteristics and 4f electron orbits shielded by 5s 2 and 5p 6 shells [1]. The lanthanide ions have a large Stokes shift and show strong, pure, long life and narrow emission bands [2].…”

A low temperature approach for photo/cathodoluminescent Gd2O2S:Tb (GOS:Tb) nanophosphors

“…This would lead to a larger volume of electron interaction and, thus, a higher CL intensity/brightness of the phosphor (Figure A,C). The penetration depth of electron beam can be assayed from the following equations: where A is the atomic or molecular weight of the compound, ρ the bulk density, E the acceleration voltage (kV), and Z the atomic number per molecule in the material. The results, calculated with Z = 160, A = 378.53, and ρ = 7.34 g/cm 3 in this work, are shown in Figure D, where it is seen that the penetration depth successively increases from ~0.3 to 183 nm with increasing acceleration voltage from 1 to 7 kV.…”

“…Though some of the above‐mentioned techniques were able to produce fine particles/crystallites of uniform size, they have the disadvantages of complicated procedure, harmful reactants, low production efficiency, and/or surface contamination by organic molecules. In this regard, the recently reported RE 2 (OH) 4 SO 4 · n H 2 O layered hydroxide sulfate (LHS; n = 0 or 2) may serve as a unique precursor for RE 2 O 2 S, since both the compounds have the same RE/S molar ratio and RE 2 O 2 S of high purity can be transformed from LHS via proper calcination with water vapor as the only by‐product. The currently available strategies for LHS synthesis are limited to refluxing a mixed solution of RE sulfate and hexamethylenetetramine and hydrothermal reaction of RE nitrate with ammonium sulfate ((NH 4 ) 2 SO 4 ) .…”

Supercritical Fluid‐Facilitated Exfoliation and Processing of 2D Materials

“…Reviews of bulk and nanoscale luminescent materials, [231] tuning luminescence in LDH materials, [232] boron nitride nanomaterial luminescence, [233] graphene-based chemiluminescence sensors, [234] layered rare-earth hydroxides, [235] and luminescence and associated mechanisms in graphene and related materials [236] have been provided. Reviews of bulk and nanoscale luminescent materials, [231] tuning luminescence in LDH materials, [232] boron nitride nanomaterial luminescence, [233] graphene-based chemiluminescence sensors, [234] layered rare-earth hydroxides, [235] and luminescence and associated mechanisms in graphene and related materials [236] have been provided.…”